A pharmacogenomic study on the polymorphic gene response to risperidone in schizophrenia patients

Risperidone is a widely used atypical antipsychotic medication, which has currently raised considerable interest in individual differences in patient response to it. Although risperidone is one of the major atypical anti-psychotics, there is a lack of pharmacogenetic studies on it, especially in Asian populations. This paper investigates the relationship between the -1438 A/G polymorphism of 5-HT2A and response to risperidone treatment. In this study, 130 schizophrenia patients were recruited, who were treated with risperidone monotherapy for eight weeks. Clinical response was assessed on the positive and negative syndrome scale (PANSS) on the day of admission and was subsequently assessed after eight weeks following the treatment. The -1438 A/G polymorphism was identified by direct sequencing. The confounding effects of nongenetic factors were estimated and the baseline symptom score was included as a covariate for adjustment. Association tests between genotype and percentage improvement in total PANSS scores, as well as positive symptom scores and negative symptom scores, were performed using analysis of variance (ANOVA). We find no significant differences in response to the treatment in terms of PANSS or subscore improvements among the subgroups according to different genotypes. Further studies on larger groups are planned to confirm the result.